1. Field of the Invention
This invention relates generally to drug compositions or formulations which have the capability of eliciting specific responses from cellular receptors and, specifically, to those optional compositions/formulations which prevent desensitization of such receptors.
2. Discussion of Relevant Art
Throughout this disclosure, I shall use terms with their generally accepted meanings and, on occasion, supplement those meanings as indicated in order to clarify a particular facet of my invention by concentrating on a specific relationship or agenda that is normally generalized by use of the term.
An agonist is a substance/drug that has affinity for and stimulates physiologic activity at cell receptors that are normally stimulated by naturally occurring substances. As used throughout, an agonist is such a substance/drug that produces a maximal or nearly maximal response, whereas an antagonist is a substance or molecule that produces no response, but can block the action of the drug-agonist. A partial agonist produces a moderate response and can also block the response of the receptor to the agonist-drug. A competitive antagonist is a substance which competes with the agonist for the receptor, but produces no response.
Present theories of receptor activation calculate the response of a receptor as some function of an agonist-receptor complex. There have been several modifications and criticisms of receptor theory (see, for example Keen, M.; Testing Models of Agonism for G-Protein Coupled Receptors: Trends Pharmacol. Sci. 12, 371-374, 1991), but none of these treatments examined the discrete change induced by ligand binding to two equilibrium states of a receptor and, consequently, no one has developed the instant (and exacting) method for determining actual drug compositions which effectively prevent desensitization of cellular receptors that are normally and incipiently responsive to a host of agonists. Careful experimental investigations of several different receptor systems have revealed that receptor theory fails to describe the observed responses in a number of cases. Also, the phenomenon of rapid desensitization has been difficult to model by modern receptor theories. Originally many of these experimental observations were reported in 1957 by del Castillo and Katz in their pioneering work on desensitization (del Castillo, J. and Katz, B. Proc. Roy. Soc. Lond. 146, 369-381, 1957). The present theories are inadequate for at least two fundamental reasons; first, they fail to describe experimental observations except for limited cases and second, they offer only a "black box" description instead of a physicochemical explanation for receptor response.
Recently, Geoffrey et al. found that competitive antagonists of a glutamate receptor decreased the desensitization of the receptor (See Geoffrey, M., et al. Molecular Pharmacology 39, 587-591; 1991). They concluded, in this study, that such paradoxical behavior could not be described by the current theories of pharmacologic action deriving from (for example) experimental observations first recorded in 1957 by del Castillo & Katz performing their pioneering work on desensitization. Until most recently, no theory has been able to adequately explain how the behavior observed by Geoffrey et al. occurs; and, the utility of mixing competitive antagonists (or partial agonists) with agonists accurately and, therefore, efficiently to prevent receptor desensitization has been all but overlooked.
Other articles which show the utility (in vivo) of using antagonist/agonist compositions, to prevent receptor desensitization, are extant. One such article is "Antitacyphylactic Effects of Progesterone and Oxytocin on Term Human Myometrial Contractile Activity In Vitro" by Xin Fu, MD, Masoumeh Rezapour, MD, Mats L ofgren, MD, PhD, Ulf ulmsten, MD, PhD, and Torbj orn B ackstr om, MD, PhD, all of the Department of Gynecology and Obstetrics, University Hospital, Uppsala, Sweden and published in Obstetrics & Gynecology (1993; 82: 532-8). Therein, Xin Fu et al. conclude that a quantum of an antagonist, progesterone, is observed to reverse the tachyphylaxis (desensitization) to oxytocin (agonist) of human myometrium. No quantification methodology is suggested for arriving at proper dosages of the antagonist for consistently achieving this reversal, however.
Another disclosure is of certain importance in the quest for in vivo studies to support modeling investigational techniques in drug research: "Beta.sub.1 and Beta.sub.2 Adrenoceptors in the Human Heart: Properties, Function, and Alterations in Chronic Heart Failure" by Otto-Erich Brodde of Bio-chemisches Forschungslabor, Medizinische Klinik and Poliklinik, Abteilung f ur Nieren-und Hochdruckkrankheiten, Universit atsklinikum, Essen, Germany. (Pharmacologic Review, 1991, Vol. 43, No. 2). This is a detailed study on chronic heart failure which discusses a recognized utility of using Beta-AR (beta-adrenergic receptor) antagonists for patients in certain types of heart failure (pp. 228-230) and which hypothesizes that such work by occupying Beta-ARs and prevent desensitization of cardiac Beta-ARs (see p.233 and references therein). No further information is detailed which would inform one of ordinary skill how to quantify the portions of antagonists necessary to fully retard i.e., prevent "down-regulation" (desensitization, ibid p. 233) of Beta-ARs. As recently as Jul. 24, 1994, the instant inventor presented his work "A Novel Biophysical Model for Receptor Activation" (R. Lanzara, CUNY, New York and BioBalance, Inc., New York, N.Y.) to the XIIth International Congress of Pharmacology at Montr eal, Qu ebec, Canada. Also presented was a paper published by him concerning Weber's Law ("Weber's Law Modeled by the Mathematical Description of a Beam Balance", Mathematical Biosciences, 122:89-94 (1994)). These works are included for their teachings on the instant concept, methods of calculation to provide quanta of antagonist: agonist necessary for achieving the objectives of the invention and demonstrate objectively by use of in vivo empirical studies that the invention is a substantial improvement to the prior art and a significant advancement in the field.
3.) Incorporation by Reference
The instant invention, being novel in its approach to solving the universally felt problem of drug receptor desensitization, is best appreciated with a thorough consideration of the works of the inventor and others. To this end, the following of the aforementioned works: Geoffroy et al. "Reduction of Desensitization of a Glutamate Ionotropic Receptor by Antagonists" Molecular Pharmacology 39: 587-91 (1991); Xin Fu et al., "Antitachyphylactic Effects of Progesterone and Oxytocin on Term Human Myometrial Contractile Activity In Vitro", Obstetrics & Gynecology, 82: 532-38 (1993); OttoErich Brodde, "Beta.sub.1 and Beta.sub.2 Adrenoceptors in the Human Heart: Properties, Function, and Alterations in Chronic Heart Failure", Pharmocological Review, Vol. 43, No. 2 (1991); Lanzara, R. "A Novel Bio-physical Model for Receptor Activation" Dept. of Allied Health Sci., CUNY, NY, N.Y. and BioBalance Inc., NY, N.Y.; and, Lanzara, R. "Weber's Law Modeled by the Mathematical Description of a Beam Balance", Mathematical Biosciences, 122: 89-94 (1994) are incorporated herein by reference.